February 17, 2012 will be remembered as the day Tobago joined the lionfish wars. A solitary specimen, approximately eight inches in length, was sighted by Keith Gibson while on a recreational dive excursion with Undersea Tobago on the windward coast. A marine biologist, Gibson admitted he had mixed feelings of surprise, excitement and foreboding upon his discovery.
This first credible report of a sighting in Tobago, will hopefully soon be confirmed by the capture of a specimen on film or spear. Divers and fishermen have been on the alert for the arrival of this fish species to our shores ever since the advisories by local fisheries officials some two years ago that indicated the southward spread of lionfish populations throughout the Caribbean Sea.
An invasive species from the Indian and Pacific Oceans, lionfish are thought to have been introduced during Hurricane Andrew in 1992, when a broken aquarium released them into Florida's Biscayne Bay. Having gained a foothold in the reefs of the Bahamas in 2004, lionfish have spread at an alarmingly rate and is the first documented non-native marine species to survive, reproduce and spread successfully. Until now, the closest reported sighting to Tobago occurred in Barbados in December 2011.
With no natural predators and an effective defence of venomous spines, they have found the coral reefs of the Caribbean to be most hospitable. Unfortunately, they are likely to negatively impact the local fish populations and by extension, the health of the reefs themselves. Lionfish are voracious eaters that can feed on fish and invertebrates up to two thirds their size, and studies in the Bahamas by the Oregon State University indicate that a single fish on a reef can reduce the juvenile fish population by 79 per cent in as little as five weeks.
A reduction of parrot fish and surgeonfish can set the stage for coral reefs to be overwhelmed by seaweed and disrupt the delicate coral reef ecosystem, a system that is already experiencing the pressures of sedimentation, coral bleaching, overfishing and nitrate pollution. A single female will spawn some two million eggs annually with hatchlings becoming sexually mature in a year. In the short-term, islands such as the Bahamas and the Caymans have resorted to encouraging the addition of lionfish to their menus in an attempt to curb populations, and in other locales, spearfishing competitions are held regularly with the sole target being the lionfish.
